I was recently reading Dr. Sarah Myhill's book on ME/CFS and she mentioned that CoQ10 is direct fuel for the mitochondria, which are the cells that actually provide energy to our bodies. 90% of people with Fibromyalgia, ME/CFS (and probably AF) suffer from mitochondrial damage. This is probably why it is helping you so much. CoQ10 is one of the cornerstones in her treatment protocol.
I was thinking of giving it a try myself, and now that I've heard your report I want to even more. My fibromyalgia has been really bad lately, and I would love to have something to take away the pain (besides pharmascueticals of course)